Resistance when administering a PPD skin test

Anyone ever have issues with resistance on your syringe when administering a PPD skin test? I work for a home health agency and do these often and every now and then when I am injecting the serum into the skin it is almost like it won't come out of the syringe. I make sure the plunger isnt stuck prior to even drawing it up. I have to push it in much harder to get it to go and then it goes in very very slow. Just curious.

That is normal especially of you are giving it correctly. It needs to be given intradermally and you should make and then see a 6-10mm bleb that will eventually dissipate. Make sure you are holding the skin taut as well. If you giveit too deep you will not make a good bleb and you will not feel that resistance you are talking about.